Real Dictionary

guy
Americans sometimes address a group of people, whether they are male or female, as guys or you guys.
countable noun: A guy is a man.

Guy in American English
a masculine name: equiv. It. & Sp. Guido
noun: a male given name: from a Germanic word meaning “ woods”

guy in American English 1
in England, an effigy of Guy Fawkes displayed and burned on Guy Fawkes Day
to make fun of; ridicule; josh; tease
noun: a man or boy; fellow

guy in American English 2
a rope, chain, rod, or wire attached to something to steady or guide it
to guide or steady with a guy
noun: a rope, cable, or appliance used to guide and steady an object being hoisted or lowered, or to secure anything likely to shift its position
transitive verb: to guide, steady, or secure with a guy or guys

Guy in British English
abbreviation for: Guyana (international car registration)
noun: Buddy, real name George Guy. born 1936, US blues singer and guitarist

guy in British English 1
noun: a man or youth
verb: to make fun of; ridicule

guy in British English 2
noun: a rope, chain, wire, etc, for anchoring an object, such as a radio mast, in position or for steadying or guiding it while being hoisted or lowered
verb: to anchor, steady, or guide with a guy or guys